Wireless, or radio, communication links are increasingly used in lieu of hardwire or other hardware links in a variety of communication modes. Because of frequency allocation crowding at lower frequencies, greater bandwidth capabilities (and therefore higher data throughputs) of higher frequencies, and advancement of technologies in higher frequency wavebands and resulting decrease in cost, gigahertz frequency wavebands are now being licensed at premium fees.
However, link quality losses related to atmospheric conditions increase significantly with signal frequency. These propagation losses are increased, for example, by the presence of water vapor, clouds, and/or rain, hail, snow, or aerosols at lower altitudes, and evolving ionospheric effects at higher altitudes.
In addition to widely used earth-based microwave links and existing satellite systems (such as the MILSTAR system), a number of new satellite systems are being proposed for implementation of ground-based communications (for example, the proposed MOTOROLA IRIDIUM, TELEDESIC, and WINSTAR systems or the like) which will operate in wavebands vulnerable to atmospheric link quality losses due to weather events. Current methods of correcting for loss of radio link quality primarily rely on correction after detecting actual loss of signal. Communication disruption is thus not prevented utilizing such current methods.
What is needed is an ability to forecast the quality of the link on a short-term basis so that the likelihood of communication link disruption or loss can be anticipated and readily mitigated (utilizing known mitigation methods such as boosting transmit power, slowing data bit rate, or switching earth station sites or satellites for example) in advance of link disruption or loss.